glibc/sysdeps/unix/sysv/linux/pthread_sigqueue.c

74 lines
2.3 KiB
C

/* Copyright (C) 2009-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <pthreadP.h>
#include <tls.h>
#include <sysdep.h>
int
pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
{
#ifdef __NR_rt_tgsigqueueinfo
struct pthread *pd = (struct pthread *) threadid;
/* Make sure the descriptor is valid. */
if (DEBUGGING_P && INVALID_TD_P (pd))
/* Not a valid thread handle. */
return ESRCH;
/* Force load of pd->tid into local variable or register. Otherwise
if a thread exits between ESRCH test and tgkill, we might return
EINVAL, because pd->tid would be cleared by the kernel. */
pid_t tid = atomic_forced_read (pd->tid);
if (__glibc_unlikely (tid <= 0))
/* Not a valid thread handle. */
return ESRCH;
/* Disallow sending the signal we use for cancellation, timers,
for the setxid implementation. */
if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
return EINVAL;
pid_t pid = getpid ();
/* Set up the siginfo_t structure. */
siginfo_t info;
memset (&info, '\0', sizeof (siginfo_t));
info.si_signo = signo;
info.si_code = SI_QUEUE;
info.si_pid = pid;
info.si_uid = getuid ();
info.si_value = value;
/* We have a special syscall to do the work. */
INTERNAL_SYSCALL_DECL (err);
int val = INTERNAL_SYSCALL_CALL (rt_tgsigqueueinfo, err, pid, tid, signo,
&info);
return (INTERNAL_SYSCALL_ERROR_P (val, err)
? INTERNAL_SYSCALL_ERRNO (val, err) : 0);
#else
return ENOSYS;
#endif
}